Circular chaser grinding gauge



March 14, 1933. G 1,901,242

CIRCULAR CHASER GRINDING GAUGE Filed June 9, 1931 Patented Mar. 14, 1933WILLIAM J. Hoes, oF'cLEvELAm), OHIO,

PANY, or CLEVELAND; OHIO, A coRroRA'rIoN or OHIO Assrenoa 'ro THENATIONAL ACME CIRCULAR oHAsER sammive G UGE Application filed me '9,

This invention relates to gauges for use with circular chasers orcutters of threading dies, the object of theinvention being to provide asimple, efficient, inexpensive and accurate micrometer gauge for usewith such circular chasers, whereby a uniform and accurate grinding ofthe chasers may be quickly and readily obtained in an expedi tiousmanner.

In thegrinding of circular Chasers, it is extremely ditficult togrind'them accurately after they have been used and for thepun poseofdetermining.theuaccuracy of this grinding and also for the purpose ofinsur-' ing the proper setting of all ofthe chasers in the die, thepresent improvement has been devised.

A further object of the invention is the provision of a gauge whichmaybe used as a guiding and gauging means for the acc u rate grindingofa series of circular chasers so that each chaser of the set or setsmay be ground precisely alike and, therefore, so positioned in the diethat they will all start cutting the work at the same time.

In the drawing accompanying and forming a part of this specification,Fig. 1 is a perspective view of this improved micrometer gauge. I J

Fig. 2 is a top view thereof illustratinga chaser in position tobe'gauged.

Fig. 3 is a cross-sectional view of the gauge showing a chaser andchaser block in position to be gauged; and Y Y Fig. 4 is a top viewillustrating the manner of grinding a circular chaser.

Similar characters of referenceindicate corresponding parts in theseveral views.

Before explaining in detail the present improvement and mode ofoperation thereof,

I desire to have it understood that the invention is not limited to thedetails of con struction and arrangement of parts which are illustratedin the accompanying draw ing since the invention is capable of otherembodiments, and that the phraseology which I employ is for the purposeof description and notoflimitation.

In the preferred. form, the micrometer gauge. comprises a suitablesupport or base 1931. Serial No. 543,098.

2 having a guideway 3 for the reception the chaser carrying-block orback carrying the circular chaser 5.

This guideway comprises a pair of parallel grooves or ways 6'open at itstop as at plate 4,

for the reception of theguide pin9 of the chaser block. W e k Carried bythesupporting block'is' an up standing apron 10 for the reception of ablunt" ended micrometer adjusting member 11 and detachably securedto theside of the block 2 is a bracket 12' for the receptio'n of a pointedmicrometer device 13, both micrometers having the usual micrometerscales for setting and reading the micromeltrsi Th'e micrometer 11v is{'inposition to act as a stop to engage the periphery of the cutter inthe manner shown in Fig. '2 and may be left in this position when anyother circular cutters ofthe same set or diameter UNITED s'rAT s PATENToFF-ICE GOM- 7, and havinga slot orrecess 8 at its bottom are to beengaged, or maybe adjusted to angle at which the chaser or cutter is; tobe placed for cutting when set into the die head. In practice, it issometimes necessary to have the cutterset in the die head so that itwill be in line with the'center line and at other times it is necessaryto have the cutter ground on an angle, this depending on the material tobe threaded. r a i The supporting base may 'be of diflerent sizesandhave various shapesof T-slotsto suit different sizes ofchasers for thevarious sizes of'die heads manufactured. I

The block is provided at both sides thereof with a threaded opening 14whereby the bracket 12 may be adjustabl-y secured to either side of theblockso thatthe micrometer gauge l3 may be used to gauge either right orleft hand cutters. In the: form shown, it is in position for right handgaug so I ing. When adjusted to the opposite side, it is in position forleft hand gauging.

In practice, when a set of chasers need grinding the one which is in thegreatest need thereof is ground first and then set into the gauge withthe micrometer 11 set at a predetermined reading according to the sizeof chaser to be gauged so that it will act as a stop. The micrometer 13is then set up against the cutting edge of thecutter to determine theamount that has been ground off after which this chaser is removed andanother chaser of the same set placed in the gauge until it contactswiththe micrometer 11 which acts as a stop and then by reading themicrometer 13, it is easily determined how much is to be ground ofi tomake this chaser precisely the same as the first one.

To eliminate overgrinding, the chasers are secured to the chaser blockby means of a serrated bushing having two different diameters asdescribed in my contemporaneously pending application filed June- 7th,1930, Serial N 0. 459,700. This serrated bushing enables the chaser tobe turned back differ ent degrees until the slightest amount of grindingwill make the chasers uniform.

This operationis then repeated with other 7 chasers of the same orother. sets so that they may all be ground and reset at the same angles,after which they are inserted in the die head andrwill all be at thesame'angle, thus enabling all of the chasers to have their cutting edgein perfect relation to the work to be operated upon and to start cuttingat the same time.

, Thus, this particular fixture is used to get a uniform grinding of thefour chasers used one set in the die head so that the cutting edge isuniform when the chasers are set in the die and all four start at thesame time. When the first chaser is ground, this chaser is put into thechecking block and so located that the micrometer screw will be set atzero. This zero line is for material such as cast ironand malleableiron.

For softer material such as screw stock the cutting edge must be groundon an angle and the chaser should be set slightly above center, which isdetermined according to the analysis of the steel. Therefore, themicrometer screw with the flat stop surface will hold the chaser inrelation to the micrometer screw so as to give an incline cut. Thispointed micrometer screw is ab- 'solutely necessary because themeasurement is taken on an angle approximately at the root diameter ofthe chaser.

Thus, by means of this'gauge, it can be readily determined just'how togrind the chasers so that they will all be uniformly ground and whenthey are applied to the die, they will all start to cut at the same timeand, further, if one chaser has been ground more than another, thiscan'be rectified, insuring that all chasers are uniformly ground anduniformly set it relation to the work.

The chasers may likewise be placed in the gauge to determine theirproper setting in the chaser block with the proper serration beforeassembling the chaser and chaser block in the die head, assuring auniform start for the thread, uniform angles of thread and perfect work.i i

It is to be understood that by describing in detail herein anyparticular form, structure or arrangement of parts, it is not intendedto limit the invention beyond the terms of the several claims or therequirements of the prior art.

In practice, by reason of the fact that the fixture is constructed toreceive both the chaser block and the chaser, the chaser can be set onits block so that it can be mounted in the die in the same position toinsure alignment of the cutting edges of all of the chasers and uniformcutting of the threads without any further adjustment. Thus this fixtureis not only used for grinding but alsofor setting the chasers in theproper position in the die.

Havingthus explained the nature of my said invention and described a wayof constructing and using the same, although without attempting to setforth all of the forms in which it may be made or all of the modes ofits use, I claim:

1. A- circular chaser gauge comprising a supporting block for thereception of an adjustable chaser block carrying slide, an.

adjustable micrometer stop carried at one end thereof, and an ad ustablemicrometer at the side thereof for determining the amount to grind offthe chaser.

2. A circular chaser gauge comprisinga supporting block for thereception of an adjustable chaser block carrying slide, an adjustablemicrometer stop carried at one end thereof, and a detachable blockcarrying an adjustable micrometer at the side thereof and attachable toeither side of said supporting block.

3. A circular chaser gauge having a chaser supporting block having aguide-way for the insertion of a chaser slide therein, an adjustablestop and an adjustable micrometer located transversely to each other onsaid block.

' 4:. A circular chaser gauge having a chaser supporting block having aguide-way for the insertion of a chaser slide therein, an adjustablemicrometer stop and an adjustable micrometer located transversely toeach other on said block.

5. Acircular chaser gauge having a chaser supporting block having aguide-way for the insertion of a chaser slide therein, an adjustableblunt ended micrometer stop and an adjustable pointed micrometer locatedtransverselyto each other on said block above said guide-way.

6. A circular chaser gauge comprising va supporting block having aguide-Way for the insertion of an inverted T-shaped chaser carryingblock, an adjustable stop at one end thereof, and an adjustablemicrometer at the side thereof.

7. A circular chaser gauge comprising a supporting block having aguide-way for the insertion of an inverted T-shaped chaser carryingblock, said block having a recess for the reception of a guide pinprojecting from said chaser carrying block, an adjustable stop at oneend thereof and an adjustable micrometer at the side thereof.

8. A circular chaser gauge comprising a supporting block having aguide-way therein for the reception of a circular chaser,

slide and a pair of micrometer adjusting devices located transversely toeach other on said block, one having a blunt end and the other a pointedend.

9. A circular chaser gauge comprising a supporting block having aguide-way therein for the reception of a circular chaser slide and apair of micrometer adjusting de-' vices located transversely to eachother on said block, one having a blunt end and the other a pointed end,and one located in line with the guide-way and the other transverselythereto.

10. A circular chaser gauge comprising a supporting block having aguide-way there- I in for the reception of a circular chaser slide and apair of micrometer adjusting devices located transversely to each otheron said block, one having a blunt end and the other a pointed end, andone located in line with the guide-way and the other transverselythereto, and detachable means for carrying the last named micrometerdevice and attachable to either side of the supporting block. 7

11. A circular chaser gauge comprising a i supporting block having apair of parallel grooves and a recess therebelow for the reception of achaser carrying member, an upstanding apron carried by said block at oneend, a blunt ended micrometer carried by said apron and projecting intoalignment with said recess and a transversely located pointed micrometerdetachably secured to the side of the block whereby it may be attachedto either side of the block for right or left hand grinding andadjustable to determine the character of the grinding to which thechaser is to be subjected.

Signed at Cleveland, Ohio, this 29th day of May, 1931. i

-WILLIAM HOGG.

